Powertrain Control Module Replacement. Chevrolet PJJ 2000

For 1990-2009 cars

Notice: In order to prevent internal damage to the PCM, the ignition must be OFF when disconnecting or reconnecting the PCM connector.

Service of the PCM should normally consist of either replacement of the PCM or EEPROM re-programming.

If the diagnostic procedures call for the PCM to be replaced, the PCM should be checked first to see if it is the correct part. DTC P0601 indicates the EEPROM programming has malfunctioned. When DTC P0601 is obtained, re-program the EEPROM.

The ignition should be OFF for at least 10 seconds before disconnecting power to the PCM so the IAC valve has time to move to the engine OFF position.

### Removal Procedure

Important: Turn the ignition switch OFF to prevent internal PCM damage when disconnecting or reconnecting power to the PCM (for example, battery cable, PCM pigtail, PCM fuse, jumper cables, etc.). The ignition switch should be OFF for at least 10 seconds before disconnecting the power to the PCM so the IAC valve has time to move to the engine OFF position.

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

1. Disconnect the negative battery cable.

Caution: To avoid any vehicle damage, serious personal injury or death when major components are removed from the vehicle and the vehicle is supported by a hoist, support the vehicle with jack stands at the opposite end from which the components are being removed and strap the vehicle to the hoist.

2. Lift the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Remove the RH engine splash shield.
4. Disconnect the horn electrical connector.
5. Remove the horn attaching bolt and the horn.

Notice: Do not touch the PCM connector pins or soldered components on the circuit board in order to prevent possible electrostatic discharge (ESD) damage. Do not remove the integrated circuit boards from the carrier.

6. Disconnect the PCM electrical connectors (1).
7. Remove the PCM retainer attaching bolts (1).
8. Slide the PCM and the retainer (1) from the PCM bracket (2).
9. Remove the retainer (1) from the PCM (2).

### Installation Procedure

Remove the Replacement PCM from its packaging and check the service number to make sure it is the same number or updated number as the malfunctioning PCM.

1. Slide the PCM (2) into the PCM retainer (1).
2. Slide the PCM and the retainer (1) into the PCM bracket (2) slots.
3. Install the PCM retainer attaching bolts (1).

Tighten
Tighten the PCM retainer attaching bolts to 8-12 N·m (6-9 lb ft).

Notice: Do not touch the PCM connector pins or soldered components on the circuit board in order to prevent possible electrostatic discharge (ESD) damage. Do not remove the integrated circuit boards from the carrier.

4. Connect the PCM electrical connectors (1).
5. Install the horn and the horn attaching bolt.

Tighten
Tighten the horn retainer bolts to 10 N·m (88 lb in).

6. Connect the horn electrical connector.
7. Install the RH engine splash shield.

Caution: To avoid any vehicle damage, serious personal injury or death when major components are removed from the vehicle and the vehicle is supported by a hoist, support the vehicle with jack stands at the opposite end from which the components are being removed and strap the vehicle to the hoist.

8. Lower the vehicle.
9. Connect the negative battery cable.
10. Reprogram the PCM and perform the Crankshaft Position System Variation Learning Procedure. Refer to Powertrain Control Module Replacement/Programming and Crankshaft Position System Variation Learn in Engines Controls.